The term telematics is often used to refer to automobile based asset tracking systems that combine global positioning system (“GPS”) satellite tracking and wireless communications for automatic roadside assistance and remote diagnostics.
Referring to FIG. 1, there is shown a block diagram illustrating a general telematics system 100 in accordance with the prior art. Typically, a telematics system 100 includes services 110, platforms 120, networks 130, auto/freight sector clients 140, and positioning technologies 150. The services 110 provided by the telematics system 100 may include automatic roadside assistance, accident notification, traffic information, diagnostics, mobile Internet access, fleet management, and navigation. The platforms 120 on which the telematics system 100 may update may include servers, gateways, and billing and customer-care call centres. The networks 130 by which communications are provided may include voice, short messaging system (“SMS”) messaging, and wireless application protocol (“WAP”). The auto/freight sector clients 140 serviced by the telematics system 100 may include passenger vehicles, trucks, freight, public safety applications. Typically, telematics systems 100 perform applications including vehicle or equipment (i.e. asset) location, driver concierge services, fleet management, and navigation/traffic information services.
Typically, an asset tracking device or module is installed in the vehicle to be tracked. The location of the device is determined by the telematics system 100 using a positioning technology 150 such as GPS or time difference of arrival (“TDOA”). The location information is then provided to an application to service a customer.
GPS technology provides specially coded satellite signals that can be processed in a GPS receiver that enables the receiver to compute position, velocity and direction. The main problem with current GPS technology is the requirement for an unobstructed view of the sky for communication with GPS satellites. Its advantage is that is can provide a location anywhere in the world without any additional infrastructure on the ground. Improved receiver performance and signal processing and new technologies, like “Enhanced GPS”, will provide locations where traditional GPS would fail.
On the other hand, TDOA uses the existing cellular network infrastructure to determine location. Referring to FIG. 2, there is shown a flow diagram illustrating a typical TDOA process 200. The process requires signal timing information from at least three different antenna sites. At step 1, a handset or vehicle places a call (e.g. a 911 call). At step 2, antennae receive the signal from the handset or vehicle and pass it to a carrier's mobile switching office. At step 3, TDOA equipment measures the difference in the time the cellular radio signals arrive at the antenna sites and translate that data into location data (i.e. longitude and latitude data). At step 4, the carrier forwards voice call and location data to a Public Safety Answering Point (“PSAP”). The use of TDOA is typically restricted to areas where coverage from multiple towers is available.
The communications networks 130 for linking tracking devices to platforms 120 to provide services 110 to customers, include cellular and telephone networks. With respect to cellular networks, network providers, such as Aeris.net™ (“Aeris”) and Cellemetry®, typically make use of the Advanced Mobile Phone System (“AMPS”) control channel frequencies for the transfer of small data packets. The use of the cellular network control channel provides more robust communication than cellular voice traffic so that it is possible to communicate with devices located in places where ordinary cell phones have marginal or intermittent voice coverage. Clients of these virtual carriers can make use of a TCP/IP data link to connect their operations centre to the virtual carrier network which then provides continent wide coverage through cellular service providers.
For example, in U.S. Pat. No. 6,131,067, to Girerd, et al, a client-server based system is described in which the location of a tracking device is determined using GPS information. This location is then reported to a user via the Internet.
While tracking assets is important, also of importance is the personal safety of users of the asset, such as a motor vehicle. It is recognized that most vehicles are or will be equipped with some form of tracking system. However, none of these systems are able to monitor the personal safety of the user from a remote location when the user is outside or some distance from the vehicle.
What is lacking in existing telematics systems and asset tracking devices, however, is a way for a user to not only locate a tracking device but also to effectively configure the tracking device to monitor the vehicle or asset or a component of the asset in which the tracking device is installed. What is also lacking is a way for asset tracking devices to monitor panic alarms generated by persons in the proximity of monitored assets.